Grafting of bentonite with a functional silane via different reaction strategies

R. OLLIER; D. D' AMICO; W, SCHROEDER; V. CYRAS; V.A. ALVAREZ

Rio de Janeiro

Conferencia; 15 ICC International Clay Conference; 2013

In this report, we analyze different strategies of modification of bentonite (Bent) combining reactions of cationic exchange, silylation and acid activation. Six samples of modified bentonite were prepared: silylated bentonite (S-Bent), acid-activated bentonite (A-Bent), exchanged clay (E-Bent), silylated and activated clay (S-A-Bent), exchanged and activated clay (E-A-Bent), and exchanged, silylated and activated bentonite (E-S-A-Bent). To study the effectiveness of the different treatments, X-rays diffraction analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy and water absorption tests were performed. After silylation reaction, regardless of whether the clay was first activated or not, the basal spacing of the layers increases and the modified clay has less surface energy presenting a significant reduction in the equilibrium water uptake percentage. The results can be markedly improved if the silylated and activated bentonite is further modified by cationic exchange reaction.